During a television interview, Ildefonso Guajardo said U.S. negotiators were under pressure to strike a new deal by the first week of May in order to give U.S. Congress members time to discuss a reworked North American Free Trade Agreement (NAFTA), given that the makeup of both chambers will change after U.S. midterm elections in November.

“We’re weeks away,” Guajardo said. “We should know if we will be able to close this by the first week of May at the latest. … There’s a very high probability, about 80 percent, that we reach an agreement in principle.”

Guajardo added that the eighth round of talks was now largely irrelevant.

“We’re in a type of permanent round,” he said. “The technical groups are working on areas like the automotive rules of origin.”

WATCH: Political pressure ramps up to achieve NAFTA deal

Negotiations to rework NAFTA began last year after President Donald Trump took office promising to take the United States out of the 1994 agreement if it could not be reworked to better serve American interests. Talks continue this week in Washington.

Reuters reported on Sunday that talks to rework NAFTA are not advanced enough for the United States, Mexico and Canada to announce a deal “in principle” at the April 13-14 Summit of the Americas in Lima, according to two people familiar with matter.